Blue Monday is a name given to the third Monday of January, marketed as “the most depressing day of the year,” but it is not scientifically real and started as a PR stunt.

What is Blue Monday?

  • The term “Blue Monday” was coined in 2005 by psychologist Cliff Arnall in collaboration with a UK travel company (Sky Travel). It was used to promote winter holiday deals by claiming they had “calculated” the saddest day of the year.
  • The day usually falls on the third Monday of January and is framed as when people feel low after the holidays, face cold weather, debt, and failed New Year’s resolutions.

Why is it called “Blue”?

  • “Blue” is commonly associated with feeling sad or low in English, so the term taps into the idea of a midwinter emotional slump.
  • The PR story suggested a combination of factors: bad weather, post‑Christmas bills, time since Christmas, broken resolutions, and low motivation, all supposedly peaking on that Monday.

The famous “formula”

  • Arnall’s team promoted a pseudo‑mathematical formula involving variables like weather WWW, debt DDD, salary ddd, time since Christmas TTT, time since failed resolutions QQQ, motivation MMM, and “need to take action” NaN_aNa​.
  • Scientists and mental health organisations widely criticise this equation as meaningless and label the whole concept as pseudoscience and marketing, not real psychology.

Is Blue Monday actually real?

  • Mental health experts stress that there is no evidence that one specific day is objectively the most depressing of the year; people experience depression and low mood across all days and seasons.
  • Organisations like the Mental Health Foundation call Blue Monday a “myth” and a PR gimmick, warning that it can trivialise serious conditions like depression by reducing them to a one‑day media trope.

Why it still trends every year

  • Media outlets and brands repeat the Blue Monday story every January because it’s catchy, easy headline material, and ties neatly into selling mood‑boosting products, trips, or wellness services.
  • At the same time, some charities and advocates use the day as a hook to talk about real mental health issues, encourage checking in on others, and remind people to seek support when they are struggling.

If you’re feeling low around Blue Monday

  • Feeling down in January can be influenced by shorter daylight, colder weather, money stress after holidays, and pressure around resolutions, with or without the “Blue Monday” label.
  • If low mood is persistent, affects sleep, appetite, work, or relationships, or includes thoughts of self‑harm, mental health resources and professionals recommend reaching out for help rather than waiting for it to “pass with the day.”

TL;DR: It is called Blue Monday because a travel company and a psychologist branded the third Monday in January as “the most depressing day of the year” using a fake formula, but experts say it is marketing, not science, even though the emotions people feel at that time of year can be very real.

Information gathered from public forums or data available on the internet and portrayed here.